Periodic table


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Periodic table

  1. 1. Periodic Table of Elements
  2. 3. gold silver helium oxygen mercury hydrogen sodium nitrogen niobium neodymium chlorine carbon
  3. 4. Elements <ul><li>Science has come along way since Aristotle’s theory of Air, Water, Fire, and Earth. </li></ul><ul><li>Scientists have identified 90 naturally occurring elements, and created about 28 others. </li></ul>
  4. 5. Elements <ul><li>The elements, alone or in combinations, make up our bodies, our world, our sun, and in fact, the entire universe. </li></ul>
  5. 6. The most abundant element in the earth’s crust is oxygen.
  6. 7. Periodic Table <ul><li>The periodic table organizes the elements in a particular way. A great deal of information about an element can be gathered from its position in the period table. </li></ul><ul><li>For example, you can predict with reasonably good accuracy the physical and chemical properties of the element. You can also predict what other elements a particular element will react with chemically. </li></ul><ul><li>Understanding the organization and plan of the periodic table will help you obtain basic information about each of the 118 known elements. </li></ul>
  7. 8. Key to the Periodic Table <ul><li>Elements are organized on the table according to their atomic number, usually found near the top of the square. </li></ul><ul><ul><li>The atomic number refers to how many protons an atom of that element has. </li></ul></ul><ul><ul><li>For instance, hydrogen has 1 proton, so it’s atomic number is 1. </li></ul></ul><ul><ul><li>The atomic number is unique to that element. No two elements have the same atomic number. </li></ul></ul>
  8. 9. What’s in a square? <ul><li>Different periodic tables can include various bits of information, but usually: </li></ul><ul><ul><li>atomic number </li></ul></ul><ul><ul><li>symbol </li></ul></ul><ul><ul><li>atomic mass </li></ul></ul><ul><ul><li>number of valence electrons </li></ul></ul><ul><ul><li>state of matter at room temperature. </li></ul></ul>
  9. 10. Atomic Number <ul><li>This refers to how many protons an atom of that element has. </li></ul><ul><li>No two elements, have the same number of protons. </li></ul>Bohr Model of Hydrogen Atom Wave Model
  10. 11. Atomic Mass <ul><li>Atomic Mass refers to the “weight” of the atom. </li></ul><ul><li>It is derived at by adding the number of protons with the number of neutrons. </li></ul>H This is a helium atom. Its atomic mass is 4 (protons plus neutrons). What is its atomic number?
  11. 12. <ul><li>View CD-ROM Atoms and Elements </li></ul>
  12. 13. Atomic Mass and Isotopes <ul><li>While most atoms have the same number of protons and neutrons, some don’t. </li></ul><ul><li>Some atoms have more or less neutrons than protons. These are called isotopes. </li></ul><ul><li>An atomic mass number with a decimal is the total of the number of protons plus the average number of neutrons. </li></ul>
  13. 14. Atomic Mass Unit (AMU) <ul><li>The unit of measurement for an atom is an AMU. It stands for atomic mass unit. </li></ul><ul><li>One AMU is equal to the mass of one proton. </li></ul>
  14. 15. Atomic Mass Unit (AMU) <ul><li>There are </li></ul><ul><li>6 X 10 23 or 600,000,000,000,000,000,000,000 amus in one gram. </li></ul><ul><li>(Remember that electrons are 2000 times smaller than one amu). </li></ul>
  15. 16. Symbols <ul><li>All elements have their own unique symbol. </li></ul><ul><li>It can consist of a single capital letter, or a capital letter and one or two lower case letters. </li></ul>C Carbon Cu Copper
  16. 17. Common Elements and Symbols
  17. 18. Valence Electrons <ul><li>The number of valence electrons an atom has may also appear in a square. </li></ul><ul><li>Valence electrons are the electrons in the outer energy level of an atom. </li></ul><ul><li>These are the electrons that are transferred or shared when atoms bond together. </li></ul>
  18. 20. Properties of Metals <ul><li>Metals are good conductors of heat and electricity. </li></ul><ul><li>Metals are shiny. </li></ul><ul><li>Metals are ductile (can be stretched into thin wires). </li></ul><ul><li>Metals are malleable (can be pounded into thin sheets). </li></ul><ul><li>A chemical property of metal is its reaction with water which results in corrosion. </li></ul>
  19. 21. Properties of Non-Metals <ul><li>Non-metals are poor conductors of heat and electricity. </li></ul><ul><li>Non-metals are not ductile or malleable. </li></ul><ul><li>Solid non-metals are brittle and break easily. </li></ul><ul><li>They are dull. </li></ul><ul><li>Many non-metals are gases. </li></ul>Sulfur
  20. 22. Properties of Metalloids <ul><li>Metalloids (metal-like) have properties of both metals and non-metals. </li></ul><ul><li>They are solids that can be shiny or dull. </li></ul><ul><li>They conduct heat and electricity better than non-metals but not as well as metals. </li></ul><ul><li>They are ductile and malleable. </li></ul>Silicon
  21. 25. Families Periods <ul><li>Columns of elements are called groups or families. </li></ul><ul><li>Elements in each family have similar but not identical properties. </li></ul><ul><li>For example, lithium (Li), sodium (Na), potassium (K), and other members of family IA are all soft, white, shiny metals. </li></ul><ul><li>All elements in a family have the same number of valence electrons. </li></ul><ul><li>Each horizontal row of elements is called a period. </li></ul><ul><li>The elements in a period are not alike in properties. </li></ul><ul><li>In fact, the properties change greatly across even given row. </li></ul><ul><li>The first element in a period is always an extremely active solid. The last element in a period, is always an inactive gas. </li></ul>
  22. 26. Families
  23. 38. Hydrogen <ul><li>The hydrogen square sits atop Family AI, but it is not a member of that family. Hydrogen is in a class of its own. </li></ul><ul><li>It’s a gas at room temperature. </li></ul><ul><li>It has one proton and one electron in its one and only energy level. </li></ul><ul><li>Hydrogen only needs 2 electrons to fill up its valence shell. </li></ul>
  24. 39. Alkali Metals <ul><li>The alkali family is found in the first column of the periodic table. </li></ul><ul><li>Atoms of the alkali metals have a single electron in their outermost level, in other words, 1 valence electron. </li></ul><ul><li>They are shiny, have the consistency of clay, and are easily cut with a knife. </li></ul>
  25. 40. Alkali Metals <ul><li>They are the most reactive metals. </li></ul><ul><li>They react violently with water. </li></ul><ul><li>Alkali metals are never found as free elements in nature. They are always bonded with another element. </li></ul>
  26. 41. What does it mean to be reactive? <ul><li>We will be describing elements according to their reactivity. </li></ul><ul><li>Elements that are reactive bond easily with other elements to make compounds. </li></ul><ul><li>Some elements are only found in nature bonded with other elements. </li></ul><ul><li>What makes an element reactive? </li></ul><ul><ul><li>An incomplete valence electron level. </li></ul></ul><ul><ul><li>All atoms (except hydrogen) want to have 8 electrons in their very outermost energy level (This is called the rule of octet.) </li></ul></ul><ul><ul><li>Atoms bond until this level is complete. Atoms with few valence electrons lose them during bonding. Atoms with 6, 7, or 8 valence electrons gain electrons during bonding. </li></ul></ul>
  27. 42. 5
  28. 45. Alkaline Earth Metals <ul><li>They are never found uncombined in nature. </li></ul><ul><li>They have two valence electrons. </li></ul><ul><li>Alkaline earth metals include magnesium and calcium, among others. </li></ul>
  29. 46. Transition Metals <ul><li>Transition Elements include those elements in the B families. </li></ul><ul><li>These are the metals you are probably most familiar: copper, tin, zinc, iron, nickel, gold, and silver. </li></ul><ul><li>They are good conductors of heat and electricity. </li></ul>
  30. 47. Transition Metals <ul><li>The compounds of transition metals are usually brightly colored and are often used to color paints. </li></ul><ul><li>Transition elements have 1 or 2 valence electrons, which they lose when they form bonds with other atoms. Some transition elements can lose electrons in their next-to-outermost level. </li></ul>
  31. 48. Transition Elements <ul><li>Transition elements have properties similar to one another and to other metals, but their properties do not fit in with those of any other family. </li></ul><ul><li>Many transition metals combine chemically with oxygen to form compounds called oxides. </li></ul>
  32. 49. Boron Family <ul><li>The Boron Family is named after the first element in the family. </li></ul><ul><li>Atoms in this family have 3 valence electrons. </li></ul><ul><li>This family includes a metalloid (boron), and the rest are metals. </li></ul><ul><li>This family includes the most abundant metal in the earth’s crust (aluminum). </li></ul>
  33. 50. Carbon Family <ul><li>Atoms of this family have 4 valence electrons. </li></ul><ul><li>This family includes a non-metal (carbon), metalloids, and metals. </li></ul><ul><li>The element carbon is called the “basis of life.” There is an entire branch of chemistry devoted to carbon compounds called organic chemistry. </li></ul>
  34. 51. Nitrogen Family <ul><li>The nitrogen family is named after the element that makes up 78% of our atmosphere. </li></ul><ul><li>This family includes non-metals, metalloids, and metals. </li></ul><ul><li>Atoms in the nitrogen family have 5 valence electrons. They tend to share electrons when they bond. </li></ul><ul><li>Other elements in this family are phosphorus, arsenic, antimony, and bismuth. </li></ul>
  35. 52. Oxygen Family <ul><li>Atoms of this family have 6 valence electrons. </li></ul><ul><li>Most elements in this family share electrons when forming compounds. </li></ul><ul><li>Oxygen is the most abundant element in the earth’s crust. It is extremely active and combines with almost all elements. </li></ul>
  36. 53. Halogen Family <ul><li>The elements in this family are fluorine, chlorine, bromine, iodine, and astatine. </li></ul><ul><li>Halogens have 7 valence electrons, which explains why they are the most active non-metals. They are never found free in nature. </li></ul><ul><li>Halogen atoms only need to gain 1 electron to fill their outermost energy level. </li></ul><ul><li>They react with alkali metals to form salts. </li></ul>
  37. 54. Noble Gases <ul><li>Noble Gases are colorless gases that are extremely un-reactive. </li></ul><ul><li>One important property of the noble gases is their inactivity. They are inactive because their outermost energy level is full. </li></ul><ul><li>Because they do not readily combine with other elements to form compounds, the noble gases are called inert. </li></ul><ul><li>The family of noble gases includes helium, neon, argon, krypton, xenon, and radon. </li></ul><ul><li>All the noble gases are found in small amounts in the earth's atmosphere. </li></ul>
  38. 55. Rare Earth Elements <ul><li>The thirty rare earth elements are composed of the lanthanide and actinide series. </li></ul><ul><li>One element of the lanthanide series and most of the elements in the actinide series are called trans-uranium, which means synthetic or man-made. </li></ul>
  39. 56. Mendeleev <ul><li>In 1869, Dmitri Ivanovitch Mendeléev created the first accepted version of the periodic table. </li></ul><ul><li>He grouped elements according to their atomic mass, and as he did, he found that the families had similar chemical properties.  </li></ul><ul><li>Blank spaces were left open to add the new elements he predicted would occur.  </li></ul>
  40. 57. Matter <ul><li>All matter is composed of atoms and groups of atoms bonded together, called molecules. </li></ul><ul><ul><li>Substances that are made from one type of atom only are called pure substances. </li></ul></ul><ul><ul><li>Substances that are made from more than one type of atom bonded together are called compounds. </li></ul></ul><ul><ul><li>Compounds that are combined physically, but not chemically, are called mixtures . </li></ul></ul>
  41. 58. Elements, Compounds, Mixtures <ul><li>Sodium is an element. </li></ul><ul><li>Chlorine is an element. </li></ul><ul><li>When sodium and chlorine bond they make the compound sodium chloride, commonly known as table salt. </li></ul> Compounds have different properties than the elements that make them up.  Table salt has different properties than sodium, an explosive metal, and chlorine, a poisonous gas.
  42. 59. Elements, Compounds, Mixtures <ul><li>Hydrogen is an element. </li></ul><ul><li>Oxygen is an element. </li></ul><ul><li>When hydrogen and oxygen bond they make the compound water. </li></ul><ul><li>When salt and water are combined, a mixture is created. Compounds in mixtures retain their individual properties. </li></ul>The ocean is a mixture.
  43. 60. Elements, compounds, and mixtures <ul><li>Mixtures can be separated by physical means. </li></ul><ul><li>Compounds can only be separated by chemical means. </li></ul><ul><li>Elements are pure substances. When the subatomic particles of an element are separated from its atom, it no longer retains the properties of that element. </li></ul>